1. Field
The present disclosure relates to a negative active material, methods of preparing the same, a negative electrode including the same, and a lithium secondary battery including the negative electrode.
2. Description of the Related Art
A currently used secondary battery includes a positive electrode, a negative electrode, an electrolyte, and a separator membrane. In the negative electrode, graphite is used as a negative active material.
Recently, research has been actively pursued to develop a high capacity silicon-based compound, a high capacity tin-based transition metal oxide, and a highly stable lithium titanium oxide (Li4Ti5O12) because the theoretical capacity of graphite has almost been reached, and the lithium secondary battery market has expanded from small-sized batteries for IT applications to medium to large-sized batteries for automobiles and power storage devices. Lithium titanium oxide has received attention because it exhibits a charge and discharge voltage 1.5 V higher than that of graphite, and has high thermal stability, high reversibility, and excellent high rate capability. However, the specific capacity of lithium titanium oxide is about 170 milliampere-hours per gram (mAh/g), and thus, titanium oxide has a lower specific capacity than currently commercialized graphite. Thus there remains a need for an improved negative electrode material.